KEY FRACTION IDEAS
1. Any number over itself always equals 1: 1 = 1
1
250
=1
250
2. Any number over 1 equals the numerator (top number):
3. The fraction bar always means “divide by:”
1468
=1
1468
13 = 13
1
432 = 432
1
1
= 1 –: 2 (top number in the box)
2
4. To turn an improper fraction into a mixed number:
1
32
1
7
)
–
:
= 7 2=32
OR 2 7
2
6
use as denominator
1
remainder becomes numerator
5. To turn a mixed number into an improper fraction, “do the circle:”
3 1 = (3 +x 1 ) = (2 x 3) + 1 = 7
2
2
2
2
6. To add and subtract fractions, the denominator always has to be the same:
1
2
=
3
6
1
3
+ 2 = 6
5
Never add or subtract the number in the denominator.
6
1 + 2 = 3
4
4
4
In some cases, you will have to find an equivalent fraction:
7. Regroup for subtraction: 6
–
1
4
=
54
4
1
–
4
6 1 = (5 4 + 1 ) = 5 5
4
4 4
4
– 3
– 3
4
4
Remember!
52 = 51
2
4
8. Multiplication. Multiply the numerators together; then multiply the denominators together.
12
1
3
3
1
1
Use cancellation where possible: 3 X 8 = 12
2 X 8 = 16
4
9. Division. Turn it into a multiplication problem with keep, change, flip:
keep flip
2 –: 1 = 2 X 2 = 4 = 1 1
(3 1 ) 3
3
2
3
change